Regeneration And Central Nervous System

The central nervous system (CNS) comprises grey matter, which contains neuron cell bodies and white matter, which contains the nerve axons. Most of the nerve axons are concentrically wrapped around by lipid-rich biological membrane, known as the myelin sheath. In the CNS, myelin is produced by oligodendrocyte. a type of glial cell. (Pfeiffer et al., 1993). These electrical insulating, multilamellar membranes significantly increase the electrical resistance, in which to prevent leakage of electrical currents from the axons, as well as decrease electrical capacitance to reduce the ability of the axons to store electrical energy (Shivane &

The central nervous system is what connects the brain to the muscles of the body. When a patient has an injury to the spinal cord, movements in certain parts of the body will be affected based on the location of the injury. If the injury affects hand motion then many day to day tasks are affected. This literature review seeks to understand how an injury to the spinal cord impacts movement, and what has been done so far to help those affected by spinal cord injuries.

Every behavior begins with biology. Our behaviors, as well as our thoughts and feelings, are produced by the actions of our brains, nerves, muscles, and glands. In this chapter we will begin our journey into the world of psychology by considering the biological makeup of the human being, including the most remarkable of human organs—the brain. We’ll consider the structure of the brain and also the methods that psychologists use to study the brain and to understand how it works.

repair or regrowth of the nerves which involves formation of new neurons, axons, myelin, glia or

1.What are the 2 main divisions of the nervous system and the basic structures that make

Studies on nerve fibers’ longitudinal growth, axons’ regeneration and structural plasticity of axons and dendrites illustrated that they are restricted to short distances and limited spatial dimensions in the CNS. Scientists recognized that neural repair required plasticity, sprouting, and regeneration, which was limited within the adult CNS. However, once adult CNS axons from multiple areas successfully regenerated into peripheral nerve grafts in the spinal cord, brain, or optic nerve, scientists discovered the key role of local tissue microenvironment in determining the extent of growth. Scientists discovered neurite growth inhibitor factors enriched in myelin such as Nogo-A, myelin proteins, MAG and OMgp, semaphorins and ephrins, and chondroitin sulphate

It is important to note that nerves in the CNS do not regenerate, while nerves in the PNS do regenerate. This is why when a person gets a cut; it completely heals in several days. But a person with spinal cord injury cannot completely heal because spinal cord does not contain neurilemma, a membrane that promotes regeneration of neurons. It was thought that the neurons would not regenerate once damaged. However, research has found that they do indeed have the ability to regenerate if scars do not obstruct the regenerative process. Scars are the result of astrocytes and

This is a picture of brain cells. There is a lot of controversy between the brain healing itself and not. There is some research that the brain tries to heal itself when damaged. Apparently brains can make new nerve cells by a process called neurogenesis. This is picture that shows neurogenesis. First the cells form. Half of the cells formed die off. Some of the cells become support cells. Only a small percent are stem cells that can become nerve cells. There is now research on new nerve-cell growth and how it can be maximized and directed toward the most damaged areas of the brain. There are rehabilitation therapies that stimulate sprouting of existing nerve cells, causing them to make connections to other nerve cells. The brain can recruit surviving parts to take over the functions of the damaged areas.

The brain and spinal cord make up the central nervous system (CNS), with the brain coordinating higher-level functions and the spinal cord relaying information from and to the peripheral nervous system (PNS). The CNS is contained within the dorsal cavity, with the brain protected by the skull and the spinal cord protected by the vertebrae. Despite this, injuries to the CNS are a global health problem because of the inability of central neurons to regenerate, unlike peripheral neurons. Injury to the CNS is initiated by mechanical impact, but the resulting cellular processes and biochemical events contribute significantly to the pathophysiology. Traumatic brain injury (TBI) and traumatic spinal cord

b. Detached axon segments remain attached for a few days after nerve injury (Rotshenker, S., 2011).

The injuries of nervous system affect many people every year and is estimated that spinal cord injuries alone affect 10,000 each year. Nerve regeneration can be achieved by production of new neurons, glia, axons, myelin, or synapses. There are differences between the functional mechanisms of peripheral nervous system (PNS) and the central nervous system (CNS). PNS has an intrinsic ability for repair and regeneration while CNS usually is incapable of self-repair and regeneration. There is currently no treatment for recovering human nerve function after injury to the CNS. Although, PNS has self-regeneration capacity, much research still needs to be performed for optimizing the environment for maximum regrowth. Injury to PNS immediately elicits the migration of phagocytes, Schwann cells, and macrophages to the lesion site in order to clear away debris such as damaged tissue [56-60].

Stem cell therapies are a promising potential treatment to fill those gaps in the circuitry on the spinal cord. They

The focal lesion created by condition #2 alongside the larger size of the guinea pig (brainstem?) would facilitate the assessment of tonotopicity for any stem cell based treatment for SGN or HC replacement.

It also could lead to a way to repair damaged nerves by cloning the nerve cells from the injured person.

Using the same techniques, we continued to explore a clinically relevant source of neurons that could be engineered into transplantable nervous tissue constructs—human DRG neurons.15 Two primary sources were sought out: (1) DRG neurons harvested from patients